Gower B A, Herd S L, Goran M I
Division of Physiology and Metabolism, Department of Nutrition Sciences, University of Alabama at Birmingham, Birmingham, Alabama 35294-3360, USA.
Obes Res. 2001 Mar;9(3):224-8. doi: 10.1038/oby.2001.25.
Relative to whites, African Americans have lower circulating triglycerides (TG) and greater highdensity lipoprotein cholesterol. The metabolic basis for this difference is not known. This study was conducted to test the hypothesis that insulin-induced suppression of free fatty acids (FFA) results in lower serum TG in African American versus white prepubertal children.
Insulin, FFA, and TG were determined at baseline and during a frequently sampled, intravenous glucose tolerance test in eight African American and eight white prepubertal males pair-matched for whole-body insulin sensitivity.
Baseline TG was lower in African Americans (0.43 +/- 0.10 vs. 0.79 +/- 0.37 mM/L; mean +/- SD; p < 0.01). African Americans had higher peak insulin (218 +/- 102 vs. 100 +/- 30 pM/L; mean +/- SD; p < 0.01) and a greater acute insulin response (9282 +/- 4272 vs. 4230 +/- 1326 pM/L x 10 minutes; mean +/- SD; p < 0.05). FFA and TG values determined at the FFA nadir were lower in African Americans (0.26 +/- 0.02 vs. 0.30 +/- 0.03 mEq/L; mean +/- SD; p < 0.01 for FFA nadir and 0.49 +/- 0.07 vs. 0.77 +/- 0.33 mM/L; mean +/- SD; p < 0.05 for TG). Among all subjects, FFA nadir was correlated with peak insulin (r = -0.54; p < 0.05). After adjusting for FFA nadir, neither baseline nor postchallenge TG differed with ethnicity (p = 0.073 and 0.192, respectively). The ethnic difference in FFA nadir disappeared after adjusting for peak insulin (p = 0.073).
These data suggest that hyperinsulinemiainduced suppression of FFA among African Americans is a determinant of lower TG in this group.
与白人相比，非裔美国人循环甘油三酯（TG）水平较低，高密度脂蛋白胆固醇水平较高。这种差异的代谢基础尚不清楚。本研究旨在检验以下假设：胰岛素诱导的游离脂肪酸（FFA）抑制导致非裔美国青春期前儿童血清TG水平低于白人儿童。
在基线时以及对8名非裔美国和8名白人青春期前男性进行频繁采样的静脉葡萄糖耐量试验期间，测定胰岛素、FFA和TG水平，这些受试者在全身胰岛素敏感性方面进行了配对匹配。
非裔美国人的基线TG水平较低（0.43±0.10 vs. 0.79±0.37 mM/L；均值±标准差；p<0.01）。非裔美国人的胰岛素峰值较高（218±102 vs. 100±30 pM/L；均值±标准差；p<0.01），急性胰岛素反应更大（9282±4272 vs. 4230±1326 pM/L×10分钟；均值±标准差；p<0.05）。在FFA最低点时测定的FFA和TG值在非裔美国人中较低（FFA最低点：0.26±0.02 vs. 0.30±0.03 mEq/L；均值±标准差；p<0.01；TG：0.49±0.07 vs. 0.77±0.33 mM/L；均值±标准差；p<0.05）。在所有受试者中，FFA最低点与胰岛素峰值相关（r = -0.54；p<0.05）。在调整FFA最低点后，基线和激发后TG在不同种族间均无差异（分别为p = 0.073和0.192）。在调整胰岛素峰值后，FFA最低点的种族差异消失（p = 0.073）。
这些数据表明，非裔美国人中高胰岛素血症诱导的FFA抑制是该组TG水平较低的一个决定因素。
